Rotary earth-boring drill



j. R. EIUII'HIIII` ROTARY EARTH BORING DRILLI APPLICATION FILED SEPT.In, 1920.

MSAIQUI PIII-mixed Aug 23. 19251@ NOQ JOH/V R 5U/VAN INVENTOR.

ATTORNEYS.

lll

UNITED STATES PATENT OFFICE.

JOHN' R. SUMAN, 0F HOUSTON, TEXAS.

ROTARY EARTH-BORING DRILL.

Application flied September 18,1920. Serial No. 411,180.

To all whom t may concern Be it lrnown that L JOHN R. SMAN, a citizen otthe United States, residing at lllouston, ltlarriscounty, Texas, haveinvented a certain new and useful Improvement in ltotary Earth-BoringDrills, of which the following is a full, clear, and exact description,such as will enable others skilled in the art to which it appertains tomake and use the same.

lilly invention relates to an improvement in drills tor boring in earth,roch, or other similaratormations in the digging of wells tor water.,oil, gas, etc.

ldy drill fs designed as a combination bit tor use in material ofditlerent degrees ol hardness. llt is an object of my invention todesign a drill for well digging which 1s adapted to work in differentcharacters ot -formation and to cut the strata evenly and with a minimumamount of vibration.

another object is 4to provide a tool ot this character havin@n cuttingmeans which are easily removable and replaceable when worn.,

another object is to provide a device ot* this character which will havemeans to discharge'the tlushing fluid at numerous points uponthe'surtace being out and in such manner as to wash the materialdirected from the cutting points. i vantages will appear from thedescription which follows:

lhieterring to the drawing, wherein like numerals ot reference areapplied to like parte throughout the several views, Figure l is acentral longitudinal section through a drill hit embodying my invention,talren on the line l-l of Fig. 2; Fig. 2 is a bottom alan view ot myinvention; llig. 3 is a central longitudinal section of a broken portionoi? the bit showing one of the cutting teeth and its methodoi'attachment; Fig. l is a top plan view ot one ott the cutting teeth;and lig. 5 is a view Showing a modilied means ot attaching the cuttingteeth to the bit.

lln the drawing I have illustrated the preterred embodiment of. myinvention, in which ll have a head l, somewhat cup-shaped inconstruction, and having the upper open end thereo'lE threaded at 3 torattachment to a drill astem .93. The cutting teeth il ot my drillproject radially from the outer surface Other objectsA and ad of thecup-shaped head so as to present theappearance of a flattened hemispherewith peg-shaped projections covering the outer surface thereof.

The cutting teeth are practically cylindrical in. shape intermediatetheir ends, the outer cutting portion being beveled, as

sho-wn particularly in Fig. 3, the beveled the bit, the teeth extendinglaterally, as'

shown at l in Fig. l, perform the larger part ot' the cutting actionwith the lower edge ot the cutting iace and, to allow tor this fact, thecutting tace is wider toward the lower portion of these teeth than atthe upper portion, as will be noted in Fig. l. The teeth are secured inposition by having the inner end 8 enlarged somewhat and htted within arecess 9, shaped to receive the same on the inner tace of the head l.The recess Sl, and the enlarged portion 8 litting therein, are shapedsomewhat oval, as shown in Fig. so as to prevent rotation of the cuttingtooth when 'fitted in position.

To retain the teeth in operative position when they have been placedwithin the head, l provide a cup-shapedv retaining member l0, spaced tolit closely against the inner face ot the head Il so as to bear againstthe inner ends ciA the teeth and hold them se- -lit within openingsV i8,formed to register withthe said dowel pins and receive the same. ln thecentral portion ot the outer lace of the head l, l have formed athreaded 'recess ll, into which l screw a specially termed tooth orpilot bit l5, the said tooth being llattened in the manner ot a fishtail liti lllll ltlti bit and pointed so `as to form a pilot memberadapted `to center and guide the bit and also to cut away efficientlythe material at the center of the hole. rllwo central channels 16 for'lushin water are provided longitudinally of this cutting tooth so as toeiiciently clear the same of material.

As will be noted from Fig. 1, the teeth fitting against the roundedouter face of the cup-shaped retaining member 10 do not con* form totheshape of the retaining member :and in order to remedy this Icontemplate I contemplate forming vthe same with concaved inner faces,conforming with the shape of the retaining member. In Fi 5, I have-showna different means of attacing the cutting teeth withinV the head. Inthis embodiment, the inner end is threaded at 19 for attachment withinthe head, it bein contemplated that the teeth will be scnewe firmlywithin the head until the cutting face is directed in the properposition for cutrlie flushin water for the bitis pumped downward] trough the hollow drill stem and throng holes 20 in the retaining memberand -the channels 6 in the teeth so as to be projected directly againstthe cutting faces thereof. As will be seen, it is possible tol form theholes 20 in the retaining member to register with the downwardlydirected` cuttingl teeth and to omit such openings in the upper rows ofteeth, which are directed laterally, it beingl contemplated that thefiushingwater, directed toward the forward cutting ed e, will besuiiicient towash these, teeth whic perform the larger part `ofthecutting action, and t0 alsofiush away the cuttings lfrom the upperteeth. It is obvious, however, that if desired openings 20 lmay beformed to register with the ends of the cutting teeth at the sides ofthe head also.

When theteeth are fitted in position, the recesses 9,'into which theheads-8 of the cutting teeth fit, will be formed in such manner that theteeth will present the cutting face in a direction radial from thecenter of the bit and directed forwardly'in thedirection of rotation ofthe bit so as to `bring the cut* ting edge 5 into contact with lthematerial in the most efficient manner. Thus when the bit is rotated theteeth 4 will act upon the 'material at the bottom of the hole and act todisintegrate the material so that it may be washed away by streams ofiushing water pumped downwardly through the 'bit and through thechannelsV in the cutting teeth, so as to wash the cutting edge thereofand to carry the material in suspension upwardly outside of the drill tothemsurface of the ground. Incase an of the cutting teeth'become dulled,it will be possible to quickly unscrew the head, remove the retainingmember and sustitute new teeth for the dulled or broken teeth, andproceed with the drilling. This form of drill will be easy torepair andsmooth and efficient in its action and, will not be liable to becomeballed up by material clogging thereabout.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. A rotary earth boring drill comprising a head, radially projectingteeth on the outer face thereof, said teeth having cutting edgespresented forwardly in the direction of rotation and means to dischargefiushing water against the cutting edges of each of said teeth. f

2. A rotar earth boring drill comprising a cup-shape head, teethprojecting radially from the forward end 'of said head, an enlargedinner end on each of said teeth fitting within recesses on the innerface of said head and a retaining member bearing against said head,-said teeth having sharp cutting edges presented in the direction ofmovement thereof.

5. A rotary earth-boring drill comprising the combination of adrillstem, a cup-shaped head secured thereon, cutting teeth projectingoutwardly from said head,and a cupshaped retaining means lining theinside of said head, said retaining means being held in fixed positionagainst said teeth by the lower end of said drill stem.

6. A rotary earth boring drill comprising the combination of a drillstem, a cup-shaped head secured thereon,cutting teeth projecting throughsaid head, a retaining means fitting closely against the inner face ofsaid head, said retaining member, head and teeth having registeredchannels to/conduct flushinghwater onto the cutting points of said teet7. A rotary earth boring drill comprising a hollow head, teethprojecting radially therefrom in forward and lateral directions, saidteeth having oval shaped inner heads M mmm id'tdmg im @wd recesses insaid Madd .mnd mmm m www Smid teeth 'm position.

d. www @nmllmborilng drill compsmg d MOHUW Madd, and mdadly projctngj =1md-,h mounted mmombly in mid' head, said www having Mh@ llowm' ends'bevled t0 pr@- mm :nllwzwd Sham@ cutting edges 'im th@ Wold@ ELU

